How much paint and how many tiles? Measuring a room

Paint

1. Measure the walls

   Wall area = perimeter × height. For a 4 × 5 m room with 2.8 m ceilings: 2 × (4 + 5) × 2.8 = 50.4 m².

2. Subtract doors and windows

   A door of about 2.0 m² and a window of 1.5 × 1.2 = 1.8 m² leave 46.6 m².

3. Multiply by coats and divide by coverage

   Two coats at about 10 m² per litre: 46.6 × 2 ÷ 10 ≈ 9.3 litres, so buy around 10 litres.

Coverage varies by paint and surface — check the figure on the tin. Rough or new plaster absorbs more paint.

Tiles

1. Measure the floor

   4 × 5 = 20 m².

2. Add waste

   Add about 10% for cuts and breakage (more for diagonal layouts): 20 × 1.10 = 22 m².

3. Convert to tiles

   With 60 × 60 cm tiles (0.36 m² each): 22 ÷ 0.36 ≈ 61.1, so buy 62 tiles — or the nearest number of full boxes.

Buy all tiles from the same batch, and keep a few spares for future repairs.

Tools for this

• Utility bill estimator